Page 97 - CITS - WCS - Mechanical

WORKSHOP SCIENCE - CITS

• Rotary Phone.
• Screwdriver.
• Drill.
• Wheelbarrow.
Differential wheel and Axle: The wheel and differential axle are secured to a shaft that runs in bearings within
a study wall mounting bracket. The necessary cords and Load hangers are provided and weights are included.
The three pulleys are fixed together to form a compound pulley.
A differential is a gear train with three drive shafts that has the property that the rotational speed of one shaft is
the average of the speeds of the others. A common use of differentials is in motor vehicles, to allow the wheels
at each end of a drive axle to rotate at different speeds while cornering. Other uses include clocks and analog
computers. Differentials can also provide a gear ratio between the input and output shafts (called the “axle ratio”
or “diff ratio”). For example, many differentials in motor vehicles provide a gearing reduction by having fewer teeth
on the pinion than the ring gear.

Worm and worm wheel: A worm gear is a thread cut into a round bar, and a worm wheel is a gear that meshed
with the worm with the worm at a shaft angle of 90 degrees. The set of a worm and worm wheel is called a worm
gear.
Worm gears are known to run smoothly and quietly, as long as they are properly mounted and lubricated. Due
to these features, typical worm gear applications include presses, small engines, lifts and elevators, rolling mills,
conveying engineering, mining industry machines, on rudders, and worm drive saws.

Rack and Pinion: Rack and pinions are used for lifting mechanisms (vertical movement), horizontal movement,
positioning mechanisms, stoppers and to permit the synchronous rotation of several shafts in general industrial
machinery. On the other hand, they are also used in steering systems to change the direction of cars.
The rack and pinion, also known as the steering rack, is an assembly in your vehicle that allows your wheels to
rotate from side to side when you turn your steering wheel.

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CITS : WCS - Mechanical - Exercise 8